More than 748,000 people have already been evacuated to the 644 evacuation centers across the country. Government officials said more than 3,000 are stranded in ports.

The U.S. Navy's Joint Typhoon Warning Center said shortly before the typhoon made landfall that its maximum sustained winds were 195 mph, with gusts up to 235 mph.

The world's strongest recorded hurricane, typhoon or cyclone to previously make landfall was Hurricane Camille of 1969, which roared ashore with 190 mph winds in Mississippi. Haiyan's sustained winds easily make it a category 5 hurricane.

The Philippines government weather bureau said Haiyan had sustained winds of 147 miles per hour, with gusts of 170 mph when it made landfall.

The U.S. Navy's numbers are different from local weather data because the Navy measures the average wind speed for one minute while local forecasters measure average for 10 minutes.

Television images from Tacloban city on Leyte Island showed a street under knee-deep floodwater carrying debris that had been blown down by the fierce winds. Tin roofing sheets ripped from buildings were flying above the street.

"Absolutely catastrophic damage must have occurred where this storm made landfall," Jeff Masters, director of meteorology at the private firm Weather Underground, told ABC News Radio.

Southern Leyte Gov. Roger Mercado said 31,000 people were evacuated in his landslide-prone mountainous province before the super typhoon struck, knocking out power, setting off small landslides that blocked roads in rural areas, uprooting trees and ripping roofs off houses around his residence.

"When you're faced with such a scenario, you can only pray, and pray and pray," Mercado told the AP by telephone, adding that his town mayors have not called in to report any major damage.

Haiyan is expected to move over South China Sea and into Vietnam by Sunday into Monday with strong winds up to 110 mph. The storm is forecast to significantly weaken as it reaches Laos and inland China, but tropical rain could produce deadly flash floods.

Haiyan is about 300 miles wide, roughly the distance from Boston to Philadelphia. The storm surge could likely exceed 23 feet, compared with the 14 feet Superstorm Sandy brought with it last year when it hit the East Coast of the U.S.

"It's stronger in an absolute sense than Sandy but the strongest winds are concentrated very close to the center as compared to a storm like Sandy where the strong winds extended very far away from the center," the National Hurricane Center's Richard Pass told ABC News Radio.

The typhoon has halted air travel as 13 of the country's airports have been shut down.

The Philippines government has three cargo planes, 32 military helicopters and planes and navy ships on standby. It's the 24th named storm this year to hit the vulnerable islands.

ABC News' Max Golembo and The Associated Press contributed to this report.